Fix end_to_end_test performance regression caused by using mutexes

net/quic/quic_end_to_end_unittest.cc

Index: net/quic/quic_end_to_end_unittest.cc
diff --git a/net/quic/quic_end_to_end_unittest.cc b/net/quic/quic_end_to_end_unittest.cc
index d6bff8aaa327f934264b247ee644fc42db77de4e..1f5cc0dfb9667f85ea670297c67a379053ff8598 100644
--- a/net/quic/quic_end_to_end_unittest.cc
+++ b/net/quic/quic_end_to_end_unittest.cc
@@ -135,10 +135,10 @@ class QuicEndToEndTest : public PlatformTest {
     server_thread_.reset(new ServerThread(server_address_, server_config_,
                                           QuicSupportedVersions(),
                                           strike_register_no_startup_period_));
-    server_thread_->Start();
-    server_thread_->WaitForServerStartup();
+    server_thread_->Initialize();
     server_address_ = IPEndPoint(server_address_.address(),
                                  server_thread_->GetPort());
+    server_thread_->Start();
     server_started_ = true;
   }